The increase in interest in GAD: Commentary on Asmundson & Asmundson

Abstract

Generalized Anxiety Disorder (GAD) is one of the most common anxiety disorders. It is associated with functional impairment and is unlikely to spontaneously remit. As identified by Asmundson and Asmundson (2018), published research studies on GAD have increased in number over the last decade. We propose that this is due to the high prevalence of the diagnosis and symptoms, interest in transdiagnostic processes, such as worry, increased interest in emotion dysregulation as a principle underlying diagnoses, and new methods of treating and disseminating treatment that may be particularly well suited to GAD. Despite the increase in research articles on GAD, GAD still remains one of the least studied anxiety disorders. We propose that this is due to the misconception that GAD does not lead to severe impairment, despite data showing otherwise. Future research should continue to examine the phenomenology, mechanisms, and treatment of GAD in order to better understand this common anxiety disorder.

1. Introduction

Generalized anxiety disorder (GAD) is one of the most common psychological diagnoses in adults, with about 6.2% of the population suffering from it at some point during their lifetime (Somers, Goldner, Waraich, & Hsu, 2006). In fact, the lifetime prevalence of this diagnosis is higher than that of all other anxiety diagnoses (Somers et al., 2006). GAD is chronic and unlikely to spontaneously remit (Newman, Llera, Erickson, Przeworski, & Castonguay, 2013). It is associated with functional impairments in interpersonal relationships and career attainment (Blazer, Hughes, & George, 1987; Przeworski et al., 2011) as well as increased rates of health problems (Newman et al., 2013).

Given its high prevalence and associated impairment, it is not surprising that Asmundson and Asmundson (2018) found that publications on GAD have been increasing since 2006. Nonetheless, despite being the most frequently experienced anxiety diagnosis, Asmundson and Asmundson (2018) highlight that between 2006 and 2016 publication numbers have lagged behind that of other anxiety diagnoses, including posttraumatic stress disorder, social anxiety disorder, and obsessive compulsive disorder. Further, as of 2000, far fewer published studies have investigated mechanisms underlying GAD and most of these have examined treatment (Dugas, 2000). The purpose of the current paper is to identify potential reasons for increasing numbers of publications on GAD as well as why other anxiety diagnoses continue to be studied more frequently than GAD.

2. GAD symptoms may be transdiagnostic

One possible reason publications have increased may be related to the transdiagnostic nature of GAD. In recent years, the field has begun to emphasize the importance of examining transdiagnostic constructs in order to better understand commonalities among diagnoses and reasons for high comorbidity among psychological disorders. This is demonstrated by NIMH’s emphasis on dimensional classification systems, such as the RDoC (Insel et al., 2010), rather than through categorical methods. Proponents of such dimensional systems suggest that common transdiagnostic factors may better capture the experience of psychological distress than categorical systems such as the DSM (American Psychiatric Association, 2013).

The worry and anxiety that characterizes GAD has been conceptualized to underlie all emotional diagnoses (Newman et al., 2013) and to be similar in nature to trait anxiety, in that both are persistent, high, and diffuse anxiety states that can impair an individual’s functioning and that may serve as a common transdiagnostic experience in anxious individuals (Newman et al., 2013). As such, the recent emphasis on transdiagnostic and dimensional approaches may have contributed to increased numbers of studies focusing on GAD.

3. Debate over the accuracy of the current DSM criteria

Another possible reason for increased publication focus is the ongoing debate about whether GAD should be a stand-alone disorder. Even when using a categorical system, there has been disagreement over the accuracy of its criteria. When GAD was introduced into DSM-III as an independent diagnosis (American Psychiatric Association, 1980) the duration for symptoms was 1 month. However, rates of comorbidity with such a short duration of symptoms led some to argue that GAD was not an independent diagnosis. Rates of comorbidity were reduced when using a 6-month duration criterion (Breslau & Davis, 1985) and some argued that the 6-month duration criterion was important in distinguishing between temporary increases in anxiety and worry in response to stress.

Arguments have been made for reducing the current duration criterion from 6 months in order to most accurately reflect the experience of GAD. This proposed change was driven by research suggesting that many individuals experience subthreshold symptoms that do not meet the 6-month duration criterion for DSM-5 GAD and that those who experience shorter duration episodes of GAD symptoms do not differ in impairment or rates of comorbidity from those meeting the 6 month duration criterion (Ruscio et al., 2007). Thus, it was argued that applying the 6 month duration criterion may lead to many distressed individuals not receiving a diagnosis or being able to pursue treatment.

In the years leading up to the release of DSM-5 (American Psychiatric Association, 2013) there was continued debate about the duration of symptoms as well as other aspects of the DSM criteria. Andrews et al. (2010) suggested that the duration criterion should be reduced to 3 months and the criterion of worry being difficult to control should be deleted because it overlapped with the criterion that worry be excessive. They also suggested adding a criterion that reflects behavioral change as a result of the worry (avoidance, preparation for feared events, etc.). Although these changes were not integrated into the final DSM-5 criteria (American Psychiatric Association, 2013), disagreement regarding the criteria for GAD has led to increased study of the phenomenology and duration of symptoms of the disorder.

4. GAD is common in undergraduate populations

Universities and colleges have been reporting a dramatic increase in the number of students who are struggling with psychological disorders (Reilly, 2018). The number of students who have sought services at a college counseling center for any type of psychological distress increased by 30% between 2009 and 2015 according to a report by the Center for Collegiate Mental Health (American College Health Association, 2016). Nearly 61% of 63,000 students in a large national survey reported experiencing overwhelming anxiety and 57.6% reported elevated stress (American College Health Association, 2017). Such symptoms are associated with poorer school performance, interpersonal functioning, and physical health (American College Health Association, 2016). These rates were higher than that of depression (45.93%), trauma (11.08%), or obsessions or compulsions (4.49%) (American College Health Association, 2017).

Although these studies did not specifically assess diagnostic criteria or parse out whether the anxiety was consistent with the symptoms of clinical or subthreshold GAD, one study did specifically examine rates of GAD symptoms and found that 7% of students screened positive for GAD in comparison to 4.1% who screened positive for panic disorder (Eisenberg, Hunt, & Speer, 2013). Another study found 8% met diagnostic criteria for GAD and another 13.7% met subthreshold levels (Kanuri, Taylor, Cohen, & Newman, 2015). Social anxiety, specific phobia, OCD, and PTSD were not assessed in these studies; therefore, it is not clear what the rates of these symptoms were.

Despite, the lack of specificity of many studies of anxiety in college aged populations, studies indicating a high frequency of overwhelming anxiety in college age samples likely indicate that there are many students experiencing clinical or subthreshold GAD symptoms. Thus, such anxiety and stress may be prompting an increase in studies on GAD as researchers in university settings and service providers at college counseling centers seek to learn more about the disorder.

5. Clinical and subthreshold GAD are common in elderly individuals

With the dramatic increase in the geriatric population over the last several decades and continued growth projected in the future, there has been an increased interest in psychological disorders and symptoms that are commonly experience in elderly individuals. GAD is one of the most common psychological disorders in elderly individuals, with 7.3% of older adults experiencing symptoms of the disorder (Bryant, Jackson, & Ames, 2008). Additionally, GAD is often not identified because its symptoms, such as fatigue, sleeping difficulties, difficulty concentrating, and muscle aches, are often present in elderly individuals who do not have GAD. This suggests challenges in assessing the symptoms of GAD in elderly adults, struggles that have been supported by studies indicating that measures of GAD that have solid psychometric properties when used in younger and middle adults often have poor psychometric properties and diagnostic accuracy in older populations (Byrne et al., 2010). This has led to an increased number of studies examining assessment tools for GAD in elderly populations. Similarly, there have been an increase in articles on assessment instruments in GAD in general and a greater emphasis on translation of measures with good psychometric properties into other languages. This indicates the emphasis placed on having new and psychometrically sound measures of GAD as well as the importance of these measures being normed in non English speaking populations.

6. Emotion regulation is considered to be a key factor in the development of GAD

Recently there has been a renewed interest in emotion dysregulation as a mechanism underlying diagnoses. Emotion Regulation is considered an RDoC principle (Insel et al., 2010). GAD has long been conceptualized as a diagnosis which functions as a means to regulate affective discomfort. Borkovec (1994) originally conceptualized GAD as a means to avoid negative affect and subsequent theories have emphasized emotion dysregulation as a key feature of GAD (see Newman & Llera, 2011 for a complete review). Additionally, a new theory—the Contrast Avoidance Model of Worry—suggests that individuals with GAD become uncomfortable when their emotions shift from a neutral or positive state to a negative state and that worrying maintains a negative state, thereby leading them to be more comfortable (Newman & Llera, 2011). Empirical evidence supports theories emphasizing emotion dysregulation and discomfort with the experience of emotional shifts as underlying GAD.

7. Treatment

Dissemination of evidence-based interventions has also become a major focus in the field, as many people with anxiety diagnoses do not receive treatment. As such, many researchers have begun to examine ways to increase access to evidence-based interventions, such as through primary care physicians providing treatment and through technology-based interventions, such as computer-assisted therapy, videoconferenced therapy, and websites. Cognitive-behavioral therapy (CBT) for GAD is skills-based and brief and, therefore, fits nicely with primary care and technology-based approaches. Additionally, new wave approaches have begun to be emphasized, including Acceptance and Commitment Therapy (ACT) and Mindfulness approaches. These approaches are particularly well-suited to GAD and may have led to the increased number of therapy-oriented publications on GAD. Finally, other novel approaches to therapy, such as yoga, various forms of exercise, and Swedish massage, are also beginning to be examined.

8. Why hasn’t it increased at the rates of other anxiety disorders?

Despite data indicating that GAD is associated with functional impairment and increased medical care, some have questioned whether GAD is truly as severe as other anxiety diagnoses and have even argued that it should be considered an extreme presentation of a normal personality trait (Akiskal, 1998). Although small studies have suggested that pure GAD is associated with less severe disability than other diagnoses, larger studies have demonstrated that the functional impairment associated with GAD is equivalent and sometimes greater than that of other diagnoses (see Newman et al., 2013 for a review). Despite this, some researchers and clinicians continue to see GAD as a diagnosis that is less severe or disabling than other anxiety diagnoses. This misconception may contribute to fewer studies being conducted on GAD than other anxiety-related diagnoses. At the same time, suggestions that GAD is not a real disorder, may also have led a lot of researchers to focus on other disorders that might be viewed by them as more important.

9. Conclusions and future directions

Although the continued growth in research examining the phenomenology, underlying mechanisms, and treatment of GAD is promising, studies examining the diagnosis have continued to be less frequent than that of other anxiety diagnoses. With high rates of the diagnosis and subthreshold GAD in geriatric populations and college students, the current interest in transdiagnostic approaches and emotion regulation difficulties underlying diagnoses, and the call for novel approaches to treatment that may increase the efficacy of intervention and aid in dissemination, it is our hope that there will be continued and even increased interest in researching GAD in the future.